494 PACA AND AGOUTI arch, "by the curving inwards of the bone^ which lodges a cavity continuous with the mouth. The palate has anteriorly a ridge on either side, and is thus divided from the sides of the face in a way which is not found -1 in the allies of Coelogenys. Clavicles are present. There are thirteen dorsal vertebrae. The incisors are coloured red in front. The animal is South American, and in that continent is limited to the Brazilian sub-region. This, the best-known" species of Paca, is called the Gualilla by the natives of Ecuador; in the same district another form is met with which the natives term Sachacui (signifying Forest Cavy). It is very often the case that a different native name expresses a real specific difference; and to the latter form. M. T. Stolztuann has given the name of C. taczanowsJeii? This form, unlilce the common Paca, which is fond of forests and low-lying ground in the neigh- bourhood of water, is alpine in habitat, living upon mountains of 6000 to 10,000 feet. It burrows in much the same way as its congener, and is greatly sought after as food, its meat possessing an "exquisite taste." It is pursued by dogs, by whose aid one of the two entrances to the burrow is guarded, and the creature is smoked out and killed with a stick. The genus Dasyprocta, containing those Rodents known as Agoutis, is divisible into several species, apparently about twelve, all of which are, like the Paeas, confined to the Neotropical region. They have, however, a much wider range within that region, and occur as far north as in Central America and in some of the West Indian Islands. They are of rather smaller size than the Paca, and are without spots. The colour is of a golden brown in some forms, but usually has a freckled, grizzled, greenish kind of appearance. , The tail is stumpy, the hind-limbs are distinctly longer than those of the Paca, and the two lateral toes have dis- appeared from, the feet—a concomitant as it seems of the Agouti's greater powers of running. The three metatarsals are closely pressed together, and the foot is as it were on the way towards the highly-modified foot of the Jerboa. The fore-feet are, how- ever, five-toed. The clavicle is rudimentary,8 whereas it is well developed in the Paca. The skull has not the peculiar modifica- tions of that of the last-mentioned type. The sternum has seven 1 Tlxere is & faint development of these ridges, but behind the palatine foramina in Dasyprocta aguti. Zool, JSoe* 1S85, p. lei. * Or absent ?